Basic Trope: The Official Couple was married, but got divorced, only to get back together and remarry.
Straight: Alice and Bobused to be married, but wound up divorced after things didn't work out between them. Brought back together by some quirk of fate, they fall back in love and ultimately decide to remarry.
Alice and Bob used to be madly in love and had a daughter, Bella. However, they went through a vicious breakup and divorced. Now Bob is dating Candy and Alice is engaged to David. Bella does everything in her power to get the two of them back together, with the support of all of Bob and Alice's friends, relatives and coworkers. In the end, they succeed in pushing the two of them back together, while Candy and David hook up.
Alice and Bob were so tired of their Awful Wedded Life that they simultaneously got the idea to light their home on fire, and left each believing the other to be dead. When they reunite, they fall in Love at First Sight and immediately remarry.
Downplayed: Alice and Bob were dating, then broke up, then start dating again.
Justified: After getting divorced, they had time to think about what made them fall in love in the first place and what they did wrong.
Inverted: Alice and Bob are mortal enemies at the start of the story, they fall in love and get married, but soon fall out of love, divorce and start trying to kill each other again.
Alice and Bob meet after a long time and seemingly have a history together. They start falling in love. Bob's friends ask him how he can stand to be around her after what happened before. Alice's friends ask her if he's still the same useless slob he always was. It turns out Alice is his former employer, who fired him.
Alice and Bob start falling in love again after their divorce, but then decide not to make the same mistake of being together a second time.
Although Bob is clearly interested in getting back together, Alice rejects him, choosing to marry David instead.
They were married too, but got a divorce when she sacked him.
Then they change their minds and decide to get married.
Zig Zagged: Bob and Alice used to be an Official Couple, but didn't get married before breaking up. They later rekindle their relationship and get married, only to struggle to get along again and get a divorce. Then they meet, fall in love, and decide to give marriage another shot. It doesn't work out. They end up Happily Divorced... and then, realizing that they're married in all but the official sense, they start considering giving it a third try...
Alice and Bob don't fall in love with each other again after their divorce.
Enforced: The censors forbid depictions of outright infidelity, so this is the only way a couple can be depicted seeing other people after having been together.
Lampshaded: "Didn't you just divorce each other?"
Invoked: Candy and David fall in Love at First Sight and secretly steer Bob and Alice back towards each other so they can hook up without coming off like a couple of shallow opportunists.
Defied: Alice and Bob decide not to get back together because of how poorly it went before.
Deconstructed: Although they rediscover their feelings for one another, neither one has actually resolved the problems that ended their original marriage. Hooking back up turns out to be a heat of the moment emotional thing, and their remarriage struggles for the same reasons. Meanwhile, those caught in the middle are deeply hurt. David in particular takes it hard, and when Alice ends up on the outs with Bob, he refuses to take her back.
Reconstructed: During their time apart, Alice and Bob both grew and matured, changing for the better and no longer doing the things that drove them apart in the first place. Because of this, they are able to rekindle their relationship, now older and wiser and better prepared for the commitment of marriage.